When the National Security Agency spying scandal broke in 2005, it revealed that the government was engaged in a sweeping program of surveillance of its own citizens. As technology advances, the ability of the government to spy on ordinary Americans is growing rapidly. The government has sophisticated methods of intercepting phone calls and Internet traffic. And the FBI has just told Congress it wants to expand its ability to monitor Web-based communications, including Facebook and Twitter, in part by requiring these services to build special “back doors” for the government to use for monitoring. We are also being observed every day by spy cameras, throughout major cities and suburban shopping malls. The public has no way of knowing how much information the government is collecting and what it is being used for.